PANETH, FRIEDRICH ADOLF

(b. Vienna, Austria, 31 August 1887; d. Mainz, Germany, 17 September 1958), radiochemistry, inorganic chemistry.

Paneth was the second of three sons of Joseph and Sophie Schwab Paneth. His father was a noted physiologist who discovered the histological cells that bear his name. Paneth completed his education at the universities of Munich and Glasgow, and received the Ph.D. from the University of Vienna in 1910. On 6 December 1913 he married Else Hartmann; the couple had two children, Eva and Heinrich Rudolph. From 1912 to 1918 Paneth served as an assistant to Stefan Meyer at the Vienna Institute for Radium Research. In 1913 he spent a short period of time with Soddy at the University of Glasgow and visited Rutherford’s laboratory in Manchester. After a brief stay at the Prague Institute of Technology, he spent three years at Hamburg University (1919–1922). He then worked at the University of Berlin, where he remained until 1929. He was invited to give the Geroge Fisher Baker lectures at Cornell University in 1926–1927.

From 1929 to 1933 Paneth was professor and director of the chemistry laboratories at the University of Königsberg. The growth of the Nazi movement, however, was a factor in his decision to leave Königsberg for good and become a guest lecturer at the Imperial College of Science and Technology in London, a position he held for five years. After serving one year as a reader in atomic chemistry at the University of London, he accepted a professorship at the University of Durham, where he remained from 1939 until 1953, when he returned to Germany as director of the Max Planck Institute for Chemistry in Mainz. From 1943 to 1945 he was head of the chemistry division of the Joint British-Canadian Atomic Energy Team in Montreal. He served as president of the joint Commission on Radioactivity, an organization of the International Council of Scientific Unions, from 1949 to 1955. He received the Lavoisier, Stas, Liebig, and Auer von Welsbach medals from the chemicals societies of France, Belgium, Germany, and Austria.

Paneth’s intellectual career manifested a progressively broader and deeper range of interests as his professional competence increased. He contributed significantly to the development of radioactive tracer techniques, synthesized and characterized new metal hydrides, and experimentally verified the existence of free radicals in the thermal decomposition of organic compounds. In subsequent research he developed methods for determining the age of rocks and meteorites by measuring the helium measurements to determing the composition of the stator sphere as a function of altitude up to 45 miles. In addition to his purely experimental research, Paneth was kennly interested in the philosophical, cosmological, and historical aspects of science. His involvement in radiochemical studies soon led him to an active interest in the history of alchemy, while his experimental work in the quantitative determination of trace amounts of helium led him to a consuming, lifelong interest in the study of meteorites, from a historical as well as a cosmological perspective. After his death a trust fund was established to administer his meteorite collection housed at the Max Planck Institute, to further and encourage research concerned with meteorites, and to augment the collection.

One of Paneth’s first papers in chemistry dealt with the acid-catalyzed rearrangement of quinidine and cinchonidine. But his work at the Radium Institute soon involved him in the study of radioactive substances. All of Paneth’s future experimental work progressed from this early research. Several unsuccessful efforts to separate radium, D and thorium B from lead and its compounds gradually led him to the realization that radium D and thorium B must be “isotopes” of lead. These studies, carried out in collaboration with the Hungarian radiochemist Georg von Hevesy, developed into the exploration of radium D and throium B as indicators to determine the solubility of the slight soluble compounds lead sulfide and lead chromate. A similar attempt to separate the radioactive products of throium led to the preparation and isolation of BiH₃ and the realizaiton that throium C and radium E were isotopes of bismuth. The yield of bismuth hydride was exceedingly low when produced by the ordinary methods of preparation; it was thus undetected for a long time, and only the use of ratioactive isotopes permitted the detection of the quantities formed.

While studying the metal hydrides of bismuth, lead tin, and polonium, paneth employed the mirror deposition technique to decompose the hydride and concnetrate the corresponding metal. Although its seems a short step from a study of the unstable metal hydrides to a study of the metal alkyls, this step took twelve years. During his stay at the University of Berlin, Paneth’s classic paper, written with Wilhelm Hofeditz, appeared (1929), announcing the preparation and identification of the free methyl radical from lead tetramethyl.

During the intervening period of time (1917–1929), Paneth worked at developing the sensitive methods for determining trace amounts of helium for which he is justly famous. Using spectroscopic techniques first, and mass spectrometry later, he successfully applied these techniques (1) to the determination of the content of natural gas from various sources, (2) to the quantitative determination of the rate of diffusion through glass, (3) to several unsuccessful efforts to measure helium produced by the attempt transmutation of various lighter elements into helium, and (4) to the quantitative determination of helium in rocks, artificial glasses, and meteorites. From 1929 to the end of his life the study of meteorites increasingly dominated his interests. He refined ever more accurately his techniques for determining the age for rocks by their helium content and the helium: radium ratio. These determinations were further refined when it was discovered that part of the 4^He is converted into 3^He by cosmicray bombardment in space. From these measurements range of 10⁸ to 10⁹ years and specualted that they were formed within the solar system. Until 1935 Paneth also continued his studies of organic free radicals (This field was later developed by the physical and organic chemists.) About this same time he succeeded in his efforts to induce artificial transmutation by obtaining measurable amounts of helium from the neutron bombardment of boron.

In 1935 paneth began to investigate trace components of the stratosphere. In an interesting series of papers he determined the He, O₃, and NO₂ content of the atmosphere and investigated the extent of gravitational separation of the components of the atmosphere. His basic finding was that there is no appreciable gravitational separation below 40 miles, while there appears to be a measurable change in relative concentration above 40 miles. Paneth subsequently returned to the field of free radical chemistry and explored the use of radioactive isotopes for the study of free radicals with the mirror removal technique. His last paper, on meteorites, appeared posthumously in Geochimica et cosmochimica acta as an introduction to a series of studies on the Breitcheid meteroite, which fell in Breitscheid, Dillkries, West Germany, On 11 August 1956.

BIBLIOGRAPHY

I. Original Works. Paneth’s principal works are Lehrbuch der Radioaktivität (Leipzig, 1923; 2nd ed., 1931), written with G. von Hevesy, trans. into English, by R. W. Lawson, as A Manual of Radioactivity (London, 1926; 2nd ed., 1938), and also into Russian and Hungarian (1924–1925); Radioelements as Indicators and Other Selected Topics in Inorganic Chemisty (New York, 1928), the George Fisher Baker lectures; “Über die Darstellung von freiem Methyl,” in Berichte der Deutschen chemischen Gesellschaft, 62B (1929), 1335–1347, written with W. Hofeditz; The Origin of Meteorites (Oxford, 1940), the Halley lectures, and “Der Meteroit von Breitscheid” in Geochimica et costmochimica acta, 17 (1959), 315–320. Chemistry and Beyond, H. Dingle and G. R. Martin, eds. (New York, 1964), is a selection of Paneth’s writings, and also contains an extensive bibliography.

II. Secondary Literature. See Otto Hahn, “Freidrich A. Paneth,” in Zeitschrift für Electrochemie, 61 (1957), 1121, written on the occasion of Paneth’s seventieth birthday; and K. Peters’ bibliographical appendix to one of Paneth’s last articles, “Hat Chladni das Pallas-Eisen in Petersburg gesehen,” in Österreichische Chemikerzeitung, 59 (1958), 289–291.

Ernest G. Spittler, S.J.

PANETH, FRIEDRICH ADOLF

(b. Vienna, Austria, 31 August 1887; d. Mainz, Germany, 17 September 1958), radiochemistry, inorganic chemistry, philosophy of science. For the original article on Paneth see DSB, vol. 10.

Unlike many chemists, Paneth was deeply interested in the historical roots and philosophical foundations of science in general and of chemistry in particular throughout his entire scientific life. This postscript will concentrate on his historical and philosophical contributions. He read primary sources from antiquity (pre-Socratics, Aristotle), the Renaissance (Robert Boyle), classical (Benedict Spinoza, Immanuel Kant, John Stuart Mill) and contemporary authors (Heinrich Rickert, Moritz Schlick, Emile Meyerson, Gaston Bachelard), and was well aware of the main achievements and developments of philosophy. His epistemological point of view can be considered as Kantian, and his philosophical writings as highly influential to modern philosophy of chemistry.

The discovery of isotopes and radioactivity meant that it was no longer strictly the case that all atoms of the elements as listed in the Periodic Table were identical. (Consider, for example, carbon-12 versus carbon-14.) In addition, in the process of radioactive decay, one element was destroyed and a new element was created. Paneth was the first to grapple with the implications of these discoveries for the most fundamental concepts in chemistry. In 1914 Paneth had published on general problems of isotopy, and in 1916 he produced a systematic survey on the concepts of element and atom in which he referred critically to the “law of substance” (Stoffgesetz). With this law, Wilhelm Ostwald had claimed that two chemical substances are identical with respect to all properties if they are identical in a few of these. Paneth explicitly denied the validity of this expression because isotopy, strictly taken, had made it invalid. However, Paneth conceded that a strict interpretation of this denial would lead to a devaluation of the concept of the element within chemistry: similar to uncreatability and indestructibility, it would also be necessary to abandon the idea that there was a limited number of basic chemical substances (1916, p. 182). Because of this dilemma, Paneth suggested the following definition of an element: Two elements are assigned with the same name if a mixture of these cannot be separated by chemical operations (1916, p. 183). It is noteworthy that this definition is operational and phenomenological. It is operational because it delivers a kind of recipe on how to treat two substance samples in order to differentiate or identify them. It is phenomenological because it uses real, macroscopic materials only, rather than an atomistic vocabulary.

Sixteen years later, however, there no longer was consensus regarding strictly phenomenological, non-atomistic approaches to the foundations of chemistry. Referring to ancient atomists and their reception, and more particularly to the theoretical work of Frantisek Wald (1861–1930) and Ostwald, Paneth said in 1931: “We wholly disregard here the deliberations of Wald and Ostwald, who depart from the usual notion of element and follow their own anti-atomistic lines of thought” (1962, p.9). The source of this quotation, a lecture presented in Königsberg titled “Die erkenntnistheoretische Stellung des chemischen Elementbegriffs” (The epistemological status of the chemical concept of element), was his main philosophical contribution. In his introduction, Paneth discussed the question of why chemistry has been of only minor interest to philosophers. He came to the conclusion that the deficient chemical knowledge of philosophers is primarily responsible for the neglect of chemistry in the humanities.

The two main topics of the Königsberg lecture were the question of persistence of elements in compounds and the problem of reduction of chemistry to physics. Referring to the former topic, Paneth suggested a dualist interpretation of the notion element. This distinction marks clearly the difference between two traditional conceptions of element that are often conflated. If one says, as did Boyle, that elements are the last products of analysis, then one is using the concept of simple substances (einfache Stoffe). However, if one thinks of elements as the ultimate constituents of matter that are invariant during chemical reactions, one is dealing with the concept of basic substances (Grundstoffe). In modern philosophical terms, simple substances are observables, basic substances are nonobservables. Here is seen a hint of the Kantian phenomena(the observables) and noumena (the non-observables). Paneth claimed: “to understand the change of properties of substances we require transcendental hypotheses” (1962, p. 14). Hence, he expanded his former merely phenomenological point of view and added the realm of transcendental ideas to his philosophy of chemistry.

Referring to reductionism, Paneth said: “Even if the essential character of chemistry should change in the future as the result of the expansion of mathematical-physical methods, its history during the nineteenth century, when it achieved such successes without mathematics, must never be ignored in its philosophic evaluation” (1962, p.8). Thus, as the result of his Kantian philosophy of science, he rejected the reduction of chemistry to physics (or mathematics) with the argument that chemistry never will lose contact to the realm of observables.

SUPPLEMENTARY BIBLIOGRAPHY

WORKS BY PANETH

“Über den Element- und Atombegriff in Chemie und Radiologie.” Zeitschrift für Physikalische Chemie 91 (1916): 171–198. Über die erkenntnistheoretische Stellung des chemischen

Elementbegriffs. Halle/Saale: Niemeyer, 1931. Published as “The Epistemological Status of the Chemical Concept.” The British Journal for the Philosophy of Science 13 (1962): 1–14, 144–160. Translated into English by Paneth’s son.

OTHER SOURCES

Ruthenberg, Klaus. “Friedrich Adolf Paneth (1887–1958).” Hyle 3 (1997): 103–106.

Scerri, Eric. “Editorial 14.” Foundations of Chemistry 5 (2003)107–111.

Schummer, Joachim. Realismus und Chemie. Würzburg:

Königshausen und Neumann, 1996.

Van Brakel, Jaap. Philosophy of Chemistry: Between the Manifest and the Scientific Image. Leuven: Leuven University Press, 2000.

Klaus Ruthenberg

PANETH, FRIEDRICH ADOLF

PANETH, FRIEDRICH ADOLF (1887–1958), Austrian physical and radioactivity chemist. Paneth, a son of Joseph Paneth, a physiologist who discovered certain histological cells which still bear his name, was born in Vienna. Both his parents were born Jews, but they brought up their children as Protestants. Paneth worked from 1912 to 1917 at the Institute for Radium Research in Vienna, where with the Hungarian chemist George Hevesy he carried out the first use of radioactive tracers to measure physical properties. From 1918 he held professorships successively at the Prague Institute of Technology, and Hamburg, Berlin, Koenigsberg universities. When the Nazis came to power in 1933 he went to London, where he worked first at the Imperial College and then as reader in atomic chemistry in the University of London. In 1939 he was appointed professor of chemistry at Durham University, where he remained for 14 years. During this time he was chairman of the chemistry division of the British Canadian atomic energy team in Montreal (1943–45). In 1947 he was elected a fellow of the Royal Society. On his retirement from Durham in 1953 he returned to Germany as director of the Max Planck Institute for Chemistry at Mainz.

Paneth's prolific output of scientific papers dealt mainly with radioactive tracers, free radicals, and neutron radiation. He developed new methods for the analysis of helium and used them to determine the age and origin of meteorites. His books include Radio-Elements as Indicators, and Other Selected Topics in Inorganic Chemistry (1928) and The Origin of Meteorites (1940).

bibliography:

H. Dingle et al. (eds.), Chemistry and Beyond (1964); H.J. Emeléus, in: Royal Society of London, Biographical Memoirs, 6 (1960), 227–46; Chemiker-Zeitung, 81 (1957), 618.

[Samuel Aaron Miller]